The advent of stand-up fastener driving tools marked a significant advance in the installation of fasteners through overlapping members and into an underlying support member, collectively referred to herein as a deck, as is conventional in the roofing and flooring industries. U.S. Pat. No. 5,302,068 entitled "Fastener Having Recessed Non-Circular Head, and Fastener-Driving Tool" issued to Janusz et al. on Apr. 12, 1994 and commonly assigned herewith, for example, discloses a stand-up screw gun generally including a trigger actuatable rotary driver, which is an industrial quality hand-held electric tool, coupled to a screw driving member, with a socket portion, by a rotatable shaft extending through an outer upper tube coupled to the rotary driver and an inner lower tube telescopingly biased away from the rotary driver by means of a compressed spring member disposed within the upper tube.
The screw driving member of U.S. Pat. No. 5,302,068 is movable from an inoperative position to an operative position relative to a nose-piece coupled to a distal end of the inner lower tube upon depressing the nose-piece against the deck so as to telescopingly move the inner lower tube toward the rotary driver against the bias of the compressed spring member. In the operative position, the socket portion engages a screw retained in a screw driving position between pivotal jaws of the nose-piece so that the screw is aligned axially with the screw driving member, whereupon continued depression of the nose-piece against the deck pivotally opens the jaws so as to release the screw and extends the screw driving member through the nose-piece, thereby driving the screw into the deck. According to a related aspect of U.S. Pat. No. 5,302,068, the screw driving member includes a spring biased centering pin with a convex end disposable in a concave recess formed in the screw head for axially centering the screw with the screw driving member, and more particularly with the socket portion thereof. In one embodiment, the convex end of the centering pin and the concave recess of the screw have complementary frusto-conical surfaces so as to rotationally orient the screw relative to the socket portion of the screw driving member, thereby facilitating engagement of the screw by the socket portion.
The stand-up screw gun of U.S. Pat. No. 5,302,068 also includes a screw feed tube disposed alongside the telescoping upper and lower tubes. An upper end of the feed tube includes a funnel to facilitate manual insertion of screws therein, wherein the screws are gravity fed from the upper end of the feed tube toward a lower end thereof, which is coupled to the nose-piece by a mounting block. A passage through the mounting block directs screws from the feed tube to the screw driving position between the pivotal jaws of the nose-piece when the screw driving member is retracted away from the nose-piece in the inoperative position. Stand-up screw guns incorporating these and other aspects of the invention disclosed in U.S. Pat. No. 5,302,068 are available commercially from ITW Buildex, Itasca, Ill. under the trademarks Autotraxx.TM. and Fastraxx.TM..
In many stand-up fastener driving tools, including the stand-up screw gun of U.S. Pat. No. 5,302,068, the operator must insert each screw into the feed tube individually, wherein a second screw cannot be inserted into the feed tube until the previously inserted screw has been driven into the deck. Feeding more than one screw into the feed tube may result in obstruction of the screw driving member as it moves between the inoperative and operative positions. And feeding a second screw into the feed tube while the screw driving member is in the operative position may prevent the screw driving member from retracting fully away from the nose-piece after installation of a previously fed screw. The inventors of the present invention recognize the desirability of eliminating the necessity of manually inserting each screw into the feed tube prior to installation, but only after a previously inserted screw has been installed into the deck, which is time consuming and distracting.
Others have endeavored to provide improved fastener loading features in stand-up fastener driving tools. U.S. Pat. No. 3,960,191 entitled "Fastener Feeding and Driving Attachment" issued to Murray on Jun. 1, 1976, commonly assigned herewith, for example, discloses a stand-up screw gun having a feed tube for retaining a plurality of screws therein. The feed tube is coupled to a nose-piece disposed on an end of a telescoping tube assembly. A pivotal arm alternately positions ears at opposite ends thereof into the feed tube during retraction and extension of the telescoping tubes, wherein the ears of the pivotal arm release one of a plurality of screws retained in the feed tube toward the nose-piece as the telescoping tube assembly is extended after installation of a previously released screw. More recently, U.S. Pat. No. 5,199,625 entitled "Fastener Driving Tool Assembly With Improved Fastener-Loading Features", issued on Apr. 6, 1993 to Dewey et al., also commonly assigned herewith, discloses a flexible tube for retaining several pins disposed therein, and for directing the pins into a slot formed in a nose-piece of a stand-up fastener driving tool. A shuttle member is movable transversely in the slot toward an aperture of the nose-piece so as to transfer a pin disposed in the slot to the aperture of the nose-piece where the pin is retained by a magnet in axial alignment with the pin driving member until the pin is engaged thereby. The shuttle permits only one pin at a time from dropping from the feed tube into the slot, which occurs when the shuttle is retracted away from the aperture of the nose-piece.
The configurations of U.S. Pat. Nos. 5,302,068 and 3,960,191 require that the screws be loaded individually into the feed tube by the operator, which is often a distracting and arduous task in the field, particularly during inclement weather conditions and at precarious work sites. And although the configurations of U.S. Pat. Nos. 5,199,625 and 3,960,191 include a fastener feed tube portion for retaining a plurality of screws or pins therein for use during tool operation, the screws or pins must be loaded, or stacked, into the feed tube in a head-to-point relationship, which limits the number of fasteners retainable therein.
The present invention is directed toward novel advancements in the art of retaining and dispensing fasteners in stand-up fastener driving tools.